Making a Trypophobia-triggering image In Blender
Tissue addon

Another possibilty would be to use the Tissue add-on.
You basically define a "component", in this case a little hole with a protruberance (the one outlined in orange) and spread it on the faces of a base mesh (suzanne, outllined in light orange).

Run the Tessellate option with the objects selected in this order, enable the merging option and then run the subsurf modifier on the result to smooth the "component".



The cool thing is that you can use whatever shape as input component.